u-boot/drivers/rtc/max313xx.c
Chris Packham d6c0d7087f drivers: rtc: max313xx: provide read8/write8
In some designs the MAX313xx RTC may need calibration to cope with
oscillator inaccuracies. Provide read8/write8 ops so that the registers
can be accessed. Because the driver covers a range of MAX313xx variants
no attempt is made to ensure the register is valid.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
2023-07-25 12:44:46 -04:00

471 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Analog Devices MAX313XX series I2C RTC driver
*
* Copyright 2022 Analog Devices Inc.
*/
#include <bcd.h>
#include <dm.h>
#include <i2c.h>
#include <rtc.h>
#include <dm/device_compat.h>
#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/kernel.h>
/* common registers */
#define MAX313XX_INT_ALARM1 BIT(0)
#define MAX313XX_INT_ALARM2 BIT(1)
#define MAX313XX_HRS_F_12_24 BIT(6)
#define MAX313XX_HRS_F_AM_PM BIT(5)
#define MAX313XX_MONTH_CENTURY BIT(7)
#define MAX313XX_TMR_CFG_ENABLE BIT(4)
#define MAX313XX_TMR_CFG_FREQ_MASK GENMASK(1, 0)
#define MAX313XX_TMR_CFG_FREQ_16HZ 0x03
#define MAX313XX_REG_MINUTE 0x01
#define MAX313XX_REG_HOUR 0x02
#define MAX313XX_TIME_SIZE 0x07
/* device specific registers */
#define MAX3134X_CFG2_REG 0x01
#define MAX3134X_CFG2_SET_RTC BIT(1)
#define MAX31341_TRICKLE_RES_MASK GENMASK(1, 0)
#define MAX31341_TRICKLE_DIODE_EN BIT(2)
#define MAX31341_TRICKLE_ENABLE_BIT BIT(3)
#define MAX31341_POWER_MGMT_REG 0x56
#define MAX31341_POWER_MGMT_TRICKLE_BIT BIT(0)
#define MAX3133X_TRICKLE_RES_MASK GENMASK(2, 1)
#define MAX3133X_TRICKLE_DIODE_EN BIT(3)
#define MAX3133X_TRICKLE_ENABLE_BIT BIT(0)
#define MAX31329_TRICKLE_ENABLE_BIT BIT(7)
#define MAX31343_TRICKLE_ENABLE_MASK GENMASK(7, 4)
#define MAX31343_TRICKLE_ENABLE_CODE 5
#define MAX31329_43_TRICKLE_RES_MASK GENMASK(1, 0)
#define MAX31329_43_TRICKLE_DIODE_EN BIT(2)
#define MAX31329_CONFIG2_REG 0x04
#define MAX31329_CONFIG2_CLKIN_EN BIT(2)
#define MAX31329_CONFIG2_CLKIN_FREQ GENMASK(1, 0)
#define MAX31341_42_CONFIG1_REG 0x00
#define MAX31341_42_CONFIG1_CLKIN_EN BIT(7)
#define MAX31341_42_CONFIG1_CLKIN_FREQ GENMASK(5, 4)
#define MAX31341_42_CONFIG1_OSC_DISABLE BIT(3)
#define MAX31341_42_CONFIG1_SWRST BIT(0)
enum max313xx_ids {
ID_MAX31328,
ID_MAX31329,
ID_MAX31331,
ID_MAX31334,
ID_MAX31341,
ID_MAX31342,
ID_MAX31343,
MAX313XX_ID_NR
};
/**
* struct chip_desc - descriptor for MAX313xx variants
* @sec_reg: Offset to seconds register. Used to denote the start of the
* current time registers.
* @alarm1_sec_reg: Offset to Alarm1 seconds register. Used to denote the
* start of the alarm registers.
* @int_en_reg: Offset to the interrupt enable register.
* @int_status_reg: Offset to the interrupt status register.
* @ram_reg: Offset to the timestamp RAM (which can be used as SRAM).
* @ram_size: Size of the timestamp RAM.
* @temp_reg: Offset to the temperature register (or 0 if temperature
* sensor is not supported).
* @trickle_reg: Offset to the trickle charger configuration register (or
* 0 if trickle charger is not supported).
* @rst_reg: Offset to the reset register.
* @rst_bit: Bit within the reset register for the software reset.
*/
struct chip_desc {
u8 sec_reg;
u8 alarm1_sec_reg;
u8 int_en_reg;
u8 int_status_reg;
u8 ram_reg;
u8 ram_size;
u8 temp_reg;
u8 trickle_reg;
u8 rst_reg;
u8 rst_bit;
};
struct max313xx_priv {
enum max313xx_ids id;
const struct chip_desc *chip;
};
static const struct chip_desc chip[MAX313XX_ID_NR] = {
[ID_MAX31328] = {
.int_en_reg = 0x0E,
.int_status_reg = 0x0F,
.sec_reg = 0x00,
.alarm1_sec_reg = 0x07,
.temp_reg = 0x11,
},
[ID_MAX31329] = {
.int_en_reg = 0x01,
.int_status_reg = 0x00,
.sec_reg = 0x06,
.alarm1_sec_reg = 0x0D,
.ram_reg = 0x22,
.ram_size = 64,
.trickle_reg = 0x19,
.rst_reg = 0x02,
.rst_bit = BIT(0),
},
[ID_MAX31331] = {
.int_en_reg = 0x01,
.int_status_reg = 0x00,
.sec_reg = 0x08,
.alarm1_sec_reg = 0x0F,
.ram_reg = 0x20,
.ram_size = 32,
.trickle_reg = 0x1B,
.rst_reg = 0x02,
.rst_bit = BIT(0),
},
[ID_MAX31334] = {
.int_en_reg = 0x01,
.int_status_reg = 0x00,
.sec_reg = 0x09,
.alarm1_sec_reg = 0x10,
.ram_reg = 0x30,
.ram_size = 32,
.trickle_reg = 0x1E,
.rst_reg = 0x02,
.rst_bit = BIT(0),
},
[ID_MAX31341] = {
.int_en_reg = 0x04,
.int_status_reg = 0x05,
.sec_reg = 0x06,
.alarm1_sec_reg = 0x0D,
.ram_reg = 0x16,
.ram_size = 64,
.trickle_reg = 0x57,
.rst_reg = 0x00,
.rst_bit = BIT(0),
},
[ID_MAX31342] = {
.int_en_reg = 0x04,
.int_status_reg = 0x05,
.sec_reg = 0x06,
.alarm1_sec_reg = 0x0D,
.rst_reg = 0x00,
.rst_bit = BIT(0),
},
[ID_MAX31343] = {
.int_en_reg = 0x01,
.int_status_reg = 0x00,
.sec_reg = 0x06,
.alarm1_sec_reg = 0x0D,
.ram_reg = 0x22,
.ram_size = 64,
.temp_reg = 0x1A,
.trickle_reg = 0x19,
.rst_reg = 0x02,
.rst_bit = BIT(0),
},
};
static const u32 max313xx_trickle_ohms[] = { 3000, 6000, 11000 };
static int max313xx_set_bits(struct udevice *dev, unsigned int reg, unsigned int bits)
{
int ret;
ret = dm_i2c_reg_read(dev, reg);
if (ret < 0)
return ret;
return dm_i2c_reg_write(dev, reg, ret | bits);
}
static int max313xx_clear_bits(struct udevice *dev, unsigned int reg, unsigned int bits)
{
int ret;
ret = dm_i2c_reg_read(dev, reg);
if (ret < 0)
return ret;
return dm_i2c_reg_write(dev, reg, ret & ~bits);
}
static int max313xx_get_hour(u8 hour_reg)
{
int hour;
/* 24Hr mode */
if (!FIELD_GET(MAX313XX_HRS_F_12_24, hour_reg))
return bcd2bin(hour_reg & 0x3f);
/* 12Hr mode */
hour = bcd2bin(hour_reg & 0x1f);
if (hour == 12)
hour = 0;
if (FIELD_GET(MAX313XX_HRS_F_AM_PM, hour_reg))
hour += 12;
return hour;
}
static int max313xx_read_time(struct udevice *dev, struct rtc_time *t)
{
struct max313xx_priv *rtc = dev_get_priv(dev);
u8 regs[7];
int ret;
ret = dm_i2c_read(dev, rtc->chip->sec_reg, regs, 7);
if (ret)
return ret;
t->tm_sec = bcd2bin(regs[0] & 0x7f);
t->tm_min = bcd2bin(regs[1] & 0x7f);
t->tm_hour = max313xx_get_hour(regs[2]);
t->tm_wday = bcd2bin(regs[3] & 0x07) - 1;
t->tm_mday = bcd2bin(regs[4] & 0x3f);
t->tm_mon = bcd2bin(regs[5] & 0x1f);
t->tm_year = bcd2bin(regs[6]) + 2000;
if (FIELD_GET(MAX313XX_MONTH_CENTURY, regs[5]))
t->tm_year += 100;
dev_dbg(dev, "read %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n",
t->tm_year, t->tm_mon, t->tm_mday,
t->tm_wday, t->tm_hour, t->tm_min, t->tm_sec);
return 0;
}
static int max313xx_set_time(struct udevice *dev, const struct rtc_time *t)
{
struct max313xx_priv *rtc = dev_get_priv(dev);
u8 regs[7];
int ret;
dev_dbg(dev, "set %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n",
t->tm_year, t->tm_mon, t->tm_mday,
t->tm_wday, t->tm_hour, t->tm_min, t->tm_sec);
if (t->tm_year < 2000) {
dev_err(dev, "year %d (before 2000) not supported\n",
t->tm_year);
return -EINVAL;
}
if (rtc->chip->rst_bit) {
ret = max313xx_clear_bits(dev, rtc->chip->rst_reg, rtc->chip->rst_bit);
if (ret)
return ret;
}
regs[0] = bin2bcd(t->tm_sec);
regs[1] = bin2bcd(t->tm_min);
regs[2] = bin2bcd(t->tm_hour);
regs[3] = bin2bcd(t->tm_wday + 1);
regs[4] = bin2bcd(t->tm_mday);
regs[5] = bin2bcd(t->tm_mon);
regs[6] = bin2bcd((t->tm_year - 2000) % 100);
if ((t->tm_year - 2000) >= 200)
regs[5] |= FIELD_PREP(MAX313XX_MONTH_CENTURY, 1);
ret = dm_i2c_write(dev, rtc->chip->sec_reg, regs, 7);
if (ret)
return ret;
switch (rtc->id) {
case ID_MAX31341:
case ID_MAX31342:
ret = max313xx_set_bits(dev, MAX3134X_CFG2_REG,
MAX3134X_CFG2_SET_RTC);
if (ret)
return ret;
udelay(10000);
ret = max313xx_clear_bits(dev, MAX3134X_CFG2_REG,
MAX3134X_CFG2_SET_RTC);
if (ret)
return ret;
break;
default:
break;
}
return ret;
}
static int max313xx_reset(struct udevice *dev)
{
struct max313xx_priv *rtc = dev_get_priv(dev);
int ret = -EINVAL;
if (rtc->chip->rst_bit)
ret = max313xx_set_bits(dev, rtc->chip->rst_reg, rtc->chip->rst_bit);
return ret;
}
static int max313xx_read8(struct udevice *dev, unsigned int reg)
{
return dm_i2c_reg_read(dev, reg);
}
static int max313xx_write8(struct udevice *dev, unsigned int reg, int val)
{
return dm_i2c_reg_write(dev, reg, val);
}
static const struct rtc_ops max3133x_rtc_ops = {
.get = max313xx_read_time,
.set = max313xx_set_time,
.reset = max313xx_reset,
.read8 = max313xx_read8,
.write8 = max313xx_write8,
};
static int max313xx_init(struct udevice *dev)
{
struct max313xx_priv *rtc = dev_get_priv(dev);
int ret;
switch (rtc->id) {
case ID_MAX31341:
case ID_MAX31342:
ret = max313xx_clear_bits(dev, MAX31341_42_CONFIG1_REG,
MAX31341_42_CONFIG1_OSC_DISABLE);
if (ret)
return ret;
return max313xx_set_bits(dev, MAX31341_42_CONFIG1_REG,
MAX31341_42_CONFIG1_SWRST);
default:
return 0;
}
}
static int max313xx_trickle_charger_setup(struct udevice *dev)
{
struct max313xx_priv *rtc = dev_get_priv(dev);
bool diode;
int index, reg;
u32 ohms;
u32 chargeable;
int ret;
if (dev_read_u32(dev, "trickle-resistor-ohms", &ohms) ||
dev_read_u32(dev, "aux-voltage-chargeable", &chargeable))
return 0;
switch (chargeable) {
case 0:
diode = false;
break;
case 1:
diode = true;
break;
default:
dev_dbg(dev, "unsupported aux-voltage-chargeable value\n");
return -EINVAL;
}
if (!rtc->chip->trickle_reg) {
dev_warn(dev, "device does not have trickle charger\n");
return -ENOTSUPP;
}
index = find_closest(ohms, max313xx_trickle_ohms,
ARRAY_SIZE(max313xx_trickle_ohms)) + 1;
switch (rtc->id) {
case ID_MAX31329:
reg = FIELD_PREP(MAX31329_TRICKLE_ENABLE_BIT, 1) |
FIELD_PREP(MAX31329_43_TRICKLE_RES_MASK, index) |
FIELD_PREP(MAX31329_43_TRICKLE_DIODE_EN, diode);
break;
case ID_MAX31331:
case ID_MAX31334:
reg = FIELD_PREP(MAX3133X_TRICKLE_ENABLE_BIT, 1) |
FIELD_PREP(MAX3133X_TRICKLE_DIODE_EN, diode) |
FIELD_PREP(MAX3133X_TRICKLE_RES_MASK, index);
break;
case ID_MAX31341:
if (index == 1)
index = 0;
reg = FIELD_PREP(MAX31341_TRICKLE_ENABLE_BIT, 1) |
FIELD_PREP(MAX31341_TRICKLE_DIODE_EN, diode) |
FIELD_PREP(MAX31341_TRICKLE_RES_MASK, index);
ret = max313xx_set_bits(dev, MAX31341_POWER_MGMT_REG,
MAX31341_POWER_MGMT_TRICKLE_BIT);
if (ret)
return ret;
break;
case ID_MAX31343:
reg = FIELD_PREP(MAX31329_43_TRICKLE_RES_MASK, index) |
FIELD_PREP(MAX31329_43_TRICKLE_DIODE_EN, diode) |
FIELD_PREP(MAX31343_TRICKLE_ENABLE_MASK,
MAX31343_TRICKLE_ENABLE_CODE);
break;
default:
return -EOPNOTSUPP;
}
return dm_i2c_reg_write(dev, rtc->chip->trickle_reg, reg);
}
static int max313xx_probe(struct udevice *dev)
{
struct max313xx_priv *max313xx = dev_get_priv(dev);
int ret;
max313xx->id = dev_get_driver_data(dev);
max313xx->chip = &chip[max313xx->id];
ret = max313xx_init(dev);
if (ret)
return ret;
return max313xx_trickle_charger_setup(dev);
}
static const struct udevice_id max313xx_of_id[] = {
{ .compatible = "adi,max31328", .data = ID_MAX31328 },
{ .compatible = "adi,max31329", .data = ID_MAX31329 },
{ .compatible = "adi,max31331", .data = ID_MAX31331 },
{ .compatible = "adi,max31334", .data = ID_MAX31334 },
{ .compatible = "adi,max31341", .data = ID_MAX31341 },
{ .compatible = "adi,max31342", .data = ID_MAX31342 },
{ .compatible = "adi,max31343", .data = ID_MAX31343 },
{ }
};
U_BOOT_DRIVER(rtc_max313xx) = {
.name = "rtc-max313xx",
.id = UCLASS_RTC,
.probe = max313xx_probe,
.of_match = max313xx_of_id,
.priv_auto = sizeof(struct max313xx_priv),
.ops = &max3133x_rtc_ops,
};